1. Field of the Invention
The present invention relates generally to optical camera systems. More specifically, the present invention relates to optical camera systems using integrated circuits (ICs) which integrate two or more separate imaging pixel arrays on a single IC chip.
2. Discussion of the Related Art
An optical camera system typically includes an optical lens or lens system, and light sensing elements. The light sensing elements can be either traditional film or integrated circuit sensors fabricated by any of a number of manufacturing processes, such as CMOS (complementary metal-oxide semiconductor) or CCD (charge-coupled device) process. Such light sensing ICs traditionally have light sensing elements, called pixels, arranged in a single one-dimensional (e.g., one row) or two-dimensional (e.g., many rows and columns) array. The pixel array is aligned with the image formed by the optical lens system and position within the focus depth of the optical system while each pixel provides an electrical output corresponding to the intensity of the incident light to which the pixel is exposed.
In a typical simple camera system, one image of an object is captured using a sensor chip having a pixel array. However, many applications require forming multiple images of the same object or forming multiple images of different objects. Such applications require using multiple cameras or, alternatively, a camera system with multiple sensor arrays. For example, a professional studio camcorder uses three sensor arrays to separately capture red, green, and blue images. As another example, a panoramic imaging system (e.g., that described in U.S. patent application Ser. No. 11/624,209) uses several sensor arrays to provide overlapping fields of view, so that a composite image may encompass a full 360° field of view.
For such applications, a conventional imaging system uses multiple single-array image sensor chips (e.g., CCD or CMOS sensors), with each sensor chip having a 2-dimensional pixel array located typically near the center of the sensor chip. In that arrangement, each sensor chip is fabricated separately and has its own signal processing chain, a digital image-processing pipeline or both. These chips are aligned and positioned carefully to accommodate the image-forming lens system. As a result, such a system has large power consumption due to duplicated signal chains on the chips. Such a system is also more complex and bulky due to difficulty in aligning multiple chips, and may be more costly to produce.
There is therefore a need for a simpler and more compact camera system that can take in multiple images.